[libvirt] [PATCH] cpu: Add support for al57 Intel features

[Feng, Shaohe]

On 2018年01月25日 22:35, Jiri Denemark wrote:
> On Fri, Jan 19, 2018 at 22:28:39 +0800, Feng, Shaohe  wrote:
>> On 2018年01月09日 18:40, Jiri Denemark wrote:
>>> On Mon, Jan 08, 2018 at 19:06:43 +0800, Feng, Shaohe  wrote:
>>>> On 2018年01月05日 02:52, John Ferlan wrote:
>>>>> On 12/17/2017 06:02 PM, Shaohe Feng wrote:
>>>>>> We can start qemu with a "cpu,+la57" to set 57-bit vitrual address
>>>>>> space. So VM can be aware that it need to enable 5-level paging.
>>>>>>
>>>>>> Corresponding QEMU commits:
>>>>>>            al57 6c7c3c21f95dd9af8a0691c0dd29b07247984122
>>>>>> ---
>>>>>>     src/cpu/cpu_map.xml | 3 +++
>>>>>>     1 file changed, 3 insertions(+)
>>>>>>
>>>>> I think if you go through history of cpu_map.xml changes you'll find
>>>>> when a new feature is added there are tests added as well - this would
>>>>> thus seemingly need a test adjustment as well.
>>>> Thanks John.
>>>> Will add tests.
>>> Adding such test usually means you go to tests/cputestdata/ directory
>>> and run "./cpu-gather.sh | ./cpu-parse.sh" which will produce several
>>> data files. Then you add a new test case in tests/cputest.c for this new
>>> CPU and regenerate the files with expected results. If you do this
>>> before adding the new feature, the patch which will then add it will
>>> nicely show the new feature gets added into the expected results of the
>>> new CPU test.
>>>
>>> Don't forget to install cpuid tool and make sure you have the latest
>>> upstream qemu installed in the system.
>>>
>>> Jirka
>> Hi Jirka,
>>
>> I went through the tests/cputestdata/ directory and found it’s for
>> defining features for different CPU models.
>>
>> However, the la57 feature is not included in any current CPUs. So I
>> think we can get waived for the tests changes?
> Hmm, I expected you had access to such host for testing...
I have checked with the KVM/qemu developer, the also have no such host.
They do their development  on an simulator.

But I did set up the libvirt env,  start a VM with la57 feature, and 
check la57 argument in the qemu command line.

>
> Anyway, ACK to the patch then with the following diff squashed in
> (apparently you didn't run make check):
>
> diff --git a/tests/domaincapsschemadata/qemu_2.9.0-tcg.x86_64.xml b/tests/domaincapsschemadata/qemu_2.9.0-tcg.x86_64.xml
> index 7ff998907d..6c2bbac190 100644
> --- a/tests/domaincapsschemadata/qemu_2.9.0-tcg.x86_64.xml
> +++ b/tests/domaincapsschemadata/qemu_2.9.0-tcg.x86_64.xml
> @@ -43,6 +43,7 @@
>         <feature policy='require' name='clwb'/>
>         <feature policy='require' name='pku'/>
>         <feature policy='require' name='ospke'/>
> +      <feature policy='require' name='la57'/>
>         <feature policy='require' name='xsaveopt'/>
>         <feature policy='require' name='xgetbv1'/>
>         <feature policy='require' name='mmxext'/>